The technical field of this invention is arthroscopy and, in particular, methods and apparatus for displaying the location of an arthroscope during use.
Arthroscopy allows for direct examination of biological structures (most commonly, the knee joint, but also the hip, shoulder, elbow and hand, as well) utilizing tiny incisions through which the arthroscope is inserted. The arthroscope contains illuminating glass fibers and a series of magnifying optical lenses that project light into the joint and relay a magnified image back to the clinician.
Conventional arthroscopes present a number of problems to the inexperienced user. Since the view from the probe is circular, it is difficult to determine the scope's orientation from the scene without actually moving the scope. Moreover, the arthroscope typically has an offset of 30.degree.; hence, the center of view is not in the direction of arthroscope motion into or out of the biological structure.
Additionally, when the arthroscope is rotated, the motion needed to manipulate the probe is not always obvious. For example, if the probe is rotated 180.degree. such that the view is "upside down" relative to the user, the motion needed to manipulate the probe is completely reversed; to move up, the user must lift the arthroscope's distal end up.
Even in the hands of a skilled practioner, the fish-eye, two-dimensional view of the arthroscope can often be uninformative; objects of interest within the joint are often not found in the field of view or hidden by other biological structures.
There exists a need for better arthroscopy systems for non-invasive and accurate examination of bone joints and other biological structures. An object of the present invention is to provide better display systems for orthopedic surgeons in the practice of arthroscopy. Another object of the present invention is to provide a teaching tool for the training of arthroscopists.
Yet another object of the invention is to provide visual systems which can enhance spatial visualization of arthroscopy, including the coordination of images seen by the surgeon through the arthroscope and varying reference points, such as natural bone structures and/or other instruments that are inserted into the observation region to perform surgical procedures.